Impact of Coronary Microvascular Dysfunction on Myocardial Strain in Patients with Heart Failure and Preserved Ejection Fraction.

Abstract

This research aimed to evaluate the role of coronary microvascular dysfunction in alteration of left ventricular (LV) myocardial deformation. This observational study involved 50 patients with LV ejection fraction (LVEF) >50% and coronary microvascular dysfunction (diagnosed by coronary angiography). TIMI frame count (TFC) was calculated for each patient. They were classified into 2 groups: 30 patients with heart failure and preserved ejection fraction (HFpEF) (cases group) and 20 patients without HF (control group). Speckle tracking echocardiography was used to evaluate LV deformation. The mean age of the studied patients was 58.8 ± 8 years. The frequency of diabetes mellitus, hypertension, and dyslipidemia were significantly higher in cases than controls. Cases had significant higher BMI (30 ± 4.48 vs. 27.3 ± 3.94 kg/m2, P=0.029). The total TFC in cases was 97.1 ± 22.9 and in controls was 79 ± 18.5, and this difference was statistically significant (P=0.005). Significantly decreased LV global strain was observed in HFpEF cases than in controls (-17.6 ± 2.14 % versus -19.5 ± 1.98%, P < 0.001). In cases with a higher TFC, the LV global strain decrease was more pronounced. There was a significant correlation between the LV global strain and total TFC (r=-0.470 and P=0.009). Patients with HFpEF exhibited higher total TFC reflecting more affected coronary microvasculature. Those patients had reduced LV global strain. Coronary microvascular dysfunction probably leads to alteration of myocardial performance.